The Continuing Debate on the Source of the Mekong

In the 1990’s, the debate about the exact location of the source of the Mekong heated up. In 1894 Frenchman Dutreuil de Rhins had come close to its discovery when he travelled through what is now the southern part of China’s Qinghai province. Since then the area had been off limits to explorers. With China opening up in the past decade they were allowed access again, and the country’s development also meant this time the Chinese were perfectly capable of doing their own research. Despite the efforts of many though, doubts still linger about the river’s source.

1994 - The Japanese, Michel Peissel and the Ganasongdou junction

In September 1994 two expeditions set out to pinpoint the source of the Mekong river. One was the initiative of the Exploration Club of Tokyo University of Agriculture, and headed by Junichi Nakanishi and Masayuki Kitamura. The other was French-British and led by Michel Peissel. These expeditions were accompanied by Chinese of the Chinese Academy of Sciences and the Qinghai Mountaineering Association respectively. The Sino-Japanese expedition (as it is courteously named by all Japanese who have written about it) was a couple of days ahead.

Both expeditions initially took the same route, reaching the Mekong just before the town of Zaduo. From there they took the dirt road to Moyun, that runs roughly parallel to the Mekong, 20 to 30 kilometres south of it. Moyun itself, a very tiny settlement, is on the bank of the river again. From Moyun all transportation has to be by yak and horse.

The Japanese went eastward, downstream along the river to the confluence of two major branches: the one they were following from Moyun, known as Zanaqu, and one joining it from the north, the Zayaqu. The spot is called Ganasongdou. Here, on September 4th, they measured width, depth and water discharge of both branches. All these indicators were much higher for the northern branch, in the case of water discharge even five times as high. They concluded they had to look for the river’s source, defined as its spot furthest from its mouth, by following this northern branch. That is what they did, and on September 12th they pinpointed the source of the Mekong at the foot of Guosongmucha Mountain, where at an altitude of 5160 m a glacier starts to melt, at longitude 94 41 37 E and latitude 33 42 41 N.

Peissel and his team arrived in Moyun on September 11th. Crucially they didn’t go to the confluence at Ganasongdou, but headed straight west, upstream along the river, in the direction where Dutreuil de Rhins had suggested the Mekong’s source to be. They chose to go this way based on maps that were likely not detailed and accurate enough. Subsequently they found a stream longer than Dutreuil de Rhins’s and claimed that in finding the beginning of this stream, on September 17th, they had discovered the source of the Mekong. It was located at the foot of Rupsa mountain pass, latitude 93 52 929 E and longitude 33 16 534 N. Peissel did not contact the Japanese and ask them about their findings, though it must be added that he was told by staff of the travel bureau of the Chinese Academy of Sciences who had organized the Japanese expedition that the Japanese had not been looking for the source of the river. Anyway, from Moyun he had not been following the main stream of the Mekong, but a tributary.

Though the Japanese had done a better job in discovering the source of the Mekong, Peissel did a much better public relations job. He managed to get all the (western) press. The prestigious British Royal Geographical Society (associated in the past with the likes of Livingstone, Scott, Mallory and Irvine) accepted his claim to have reached the source. In 1997 he published his book ‘The Last Barbarians. The Discovery of the Source of the Mekong in Tibet’. It is an exciting account of his expedition, during which inhospitable country, disease and none too reliable local contacts all conspire against him. In the eyes of the wider (western) public it was Peissel who had discovered the source of the Mekong.

1999 - The Chinese and the Yeyongsongdou junction

In this situation the Chinese stepped in. To settle the matter they were going to do their own research. No doubt they must also have felt embarrassed. Finding the source of one of the world’s greatest rivers is a major geographical discovery, and now foreigners had made that discovery on Chinese soil.

In July 1999 two expeditions were dispatched under different wings of the Chinese Academy of Sciences. This time around domestic Chinese debate would ensue. Measurements at the Ganasongdou confluence confirmed the findings of the Sino-Japanese expedition: the source of the Mekong had to be up the Zayaqu, the branch coming from the north. But the discussion now shifted to yet another confluence, 77 km upstream to the north. At a spot called Yeyongsongdou two streams join each other. The Gaoshanxigu flows from the east, its head is at the foot of Guosongmucha Mountain and this is the place identified by the Sino-Japanese expedition five years earlier as the source of the Mekong. The Gaodepu flows from the north at first and then from the east as well. Its head is at the foot of Jifu Mountain.

The Dexiang team, named after its sponsor a business group from Tianjin, measured a twenty percent higher water discharge of the Gaoshanxigu at Yeyongsongdou. They also found this stream’s basin area and glacial area to be considerably bigger than those of the Gaodepu. And they measured its total length to be 22.59 km, as opposed to 21.62 km for the Gaodepu. So they concluded the Gaoshanxigu is the main stream and pinpointed the source of the Mekong at just about the same place as the Sino-Japanese expedition. Coordinates: longitude 94 41 44 E, latitude 33 42 31N. But the team led by Dr. Liu Shaochuang came up with different findings. They twice measured the water discharge at the Yeyongsongdou junction but observed “no difference to take note of”. And according to them the length of the Gaoshanxigu was 21.50 km, and that of the Gaodepu 23.60 km. They therefore claimed the source of the Mekong was at the head of the Gaodepu, at the foot of Jifu Mountain, longitude 94 41 12 E and latitude 33 45 35 N.

It was up to the ‘Commission for Integrated Survey of Natural Resources of the Chinese Academy of Sciences’ to choose between these two claims. It may have been convinced by the survey and research of the Dexiang expedition that seemed to have more scientific basis. Also, Chinese researcher Zhou Changjin went up to Yeyongsongdou later that summer to measure once more relative discharges of the two tributaries. His results for the Gaoshanxigu were higher. Reportedly he went there after the Dexiang team and the Liu team had agreed to accept the branch with the higher discharge as the source river, because the difference in their lengths was so small.

In October 1999, the commission recognized the findings of the Dexiang group: they had pinpointed the source of the Mekong.

2007 - Liu and Wong, satellite imagery and some lingering doubts

 

If indeed Dr. Liu did agree in 1999 to accept water discharge as the deciding factor, he must have changed his mind. And in case he didn't agree at the time, he was simply undeterred. He returned to the headwaters of the Mekong in 2002. He also led a group of people that used satellite imagery to calculate the total length of the Mekong (4.909 km), as well as the length of each of its upstream tributaries that could possibly compete for the title ‘source of the Mekong’. In his 2007 article he stuck to his previous conclusions. The Mekong originates at the foot of Jifu Mountain, at the head of the Gaodepu, longitude 94 40 52 N, latitude 33 45 48 N and altitude 5200 metres. He now published as length of the Gaodepu 22.6 km, and of the Gaoshanxigu 21.0 km. Whereas in 1999 he had measured “no difference to take note of” in water discharge, in his 2007 article he states the Gaodepu is also “the branch with the greatest flow of the water”, though he does not back this up with numbers.

Liu’s findings based on satellite imagery seem reliable. Indeed they have been confirmed by Martin Ruzek of the Hongkong based China Exploration and Research Society, the organisation of renowned China explorer Wong How Man, who among many other exploits ‘relocated’ the source of the Yangtze. But when it comes to investigations on the ground, the research of the Dexiang group seemed more convincing than Liu’s in 1999. Even if Liu’s 2002 survey has been more thorough, it is still a mystery how two well equipped expeditions, run by professionals can come up with such a radically opposite result. Wong How Man, who travelled to the source in summer 2007, has expressed his disappointment that Liu, despite citing his own “thorough investigations on-the-spot”, has published neither research data, nor photo’s of the Mekong’s spring. Interestingly, Wong himself observed the Gaoshanxigu has a much larger water flow, contrary to Liu who claims the Gaodepu is the stream with the greatest discharge.

Maybe the contradictions field research has produced constitute enough reason for yet another expedition to the Mekong’s headwaters. Wong himself sees several other valid reasons, among them authentication of the source and the study of changes that may occur over time. He has also suggested the Mekong may present a case for a duo or multi- source theory. The final word on the source of the Mekong has yet to be spoken.

An Article about the Dispute

I have sent a somewhat polemic article about the way this dispute takes place to some of the main players; including speculation where things (and indeed the source of the river itself) may move from here. Together with the response that created you can read that here.